1. Field of the Invention
The present invention relates to a laser oscillator system for use in machining workpieces, and more particularly to a laser oscillator system having a laser oscillator and a frame supporting the laser oscillator, the frame being prevented from being deformed due to the heat of the laser oscillator.
2. Description of the Related Art
FIG. 3 of the accompanying drawings illustrates a conventional high-power laser oscillator system 10 for machining workpieces. As shown in FIG. 3, the laser oscillator system 10 has a casing 12 and an elongate frame 14 mounted in the casing 12 and extending in a direction normal to the sheet of FIG. 3. The frame 14 is of a hollow structure having a substantially square cross section, and has a plurality tubes 16a, 16b, 16c, 16d disposed in respective corners thereof for passing a coolant therethrough. A laser oscillator 20 is fixedly mounted on the frame 14 by a plurality of support legs 18. A mirror box 22 is disposed above the laser oscillator 20 for applying a laser beam emitted from the laser oscillator 20 and reflected by a mirror (not shown) upwardly of the laser oscillator 20 to a predetermined position.
While the laser oscillator system 10 is in operation, heat is transferred from the laser oscillator 20 to the frame 14 via the support legs 18 or through radiation, and the temperature of the frame 14 rises to the point where the frame 14 may be distorted due to thermal expansion thereof. When the frame 14 is thus distorted, the laser beam emitted from the laser oscillator 20 supported on the frame 14 changes its path, and the laser beam emitted from the laser oscillator system 10 will not be applied to the predetermined position. As a result, the quality of a workpiece which is being machined, e.g., welded, cut, etc., by the laser beam tends to be undesirably lowered.